2 * Copyright (C) 2005-2011 Team XBMC
5 * This Program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2, or (at your option)
10 * This Program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with XBMC; see the file COPYING. If not, write to
17 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
18 * http://www.gnu.org/copyleft/gpl.html
26 #include "threads/Condition.h"
28 // forward declare the CEventGroup
36 * This is an Event class built from a ConditionVariable. The Event adds the state
37 * that the condition is gating as well as the mutex/lock.
39 * This Event can be 'interruptible' (even though there is only a single place
40 * in the code that uses this behavior).
42 * This class manages 'spurious returns' from the condition variable.
47 volatile bool signaled;
48 unsigned int numWaits;
50 CCriticalSection groupListMutex; // lock for the groups list
51 std::vector<XbmcThreads::CEventGroup*> * groups;
54 * To satisfy the TightConditionVariable requirements and allow the
55 * predicate being monitored to include both the signaled and interrupted
58 XbmcThreads::TightConditionVariable<volatile bool&> condVar;
59 CCriticalSection mutex;
61 friend class XbmcThreads::CEventGroup;
63 void addGroup(XbmcThreads::CEventGroup* group);
64 void removeGroup(XbmcThreads::CEventGroup* group);
66 // helper for the two wait methods
67 inline bool prepReturn() { bool ret = signaled; if (!manualReset && numWaits == 0) signaled = false; return ret; }
69 // block the ability to copy
70 inline CEvent& operator=(const CEvent& src) { return *this; }
71 inline CEvent(const CEvent& other): condVar(signaled) {}
74 inline CEvent(bool manual = false, bool signaled_ = false) :
75 manualReset(manual), signaled(signaled_), numWaits(0), groups(NULL), condVar(signaled) {}
77 inline void Reset() { CSingleLock lock(mutex); signaled = false; }
81 * This will wait up to 'milliSeconds' milliseconds for the Event
82 * to be triggered. The method will return 'true' if the Event
83 * was triggered. Otherwise it will return false.
85 inline bool WaitMSec(unsigned int milliSeconds)
86 { CSingleLock lock(mutex); numWaits++; condVar.wait(mutex,milliSeconds); numWaits--; return prepReturn(); }
89 * This will wait for the Event to be triggered. The method will return
90 * 'true' if the Event was triggered. If it was either interrupted
91 * it will return false. Otherwise it will return false.
94 { CSingleLock lock(mutex); numWaits++; condVar.wait(mutex); numWaits--; return prepReturn(); }
101 * CEventGroup is a means of grouping CEvents to wait on them together.
102 * It is equivalent to WaitOnMultipleObject that returns when "any" Event
103 * in the group signaled.
107 std::vector<CEvent*> events;
109 XbmcThreads::TightConditionVariable<CEvent*&> condVar;
110 CCriticalSection mutex;
112 unsigned int numWaits;
114 // This is ONLY called from CEvent::Set.
115 inline void Set(CEvent* child) { CSingleLock l(mutex); signaled = child; condVar.notifyAll(); }
117 friend class ::CEvent;
122 * Create a CEventGroup from a number of CEvents. num is the number
123 * of Events that follow. E.g.:
125 * CEventGroup g(3, event1, event2, event3);
127 CEventGroup(int num, CEvent* v1, ...);
130 * Create a CEventGroup from a number of CEvents. The parameters
131 * should form a NULL terminated list of CEvent*'s
133 * CEventGroup g(event1, event2, event3, NULL);
135 CEventGroup(CEvent* v1, ...);
139 * This will block until any one of the CEvents in the group are
140 * signaled at which point a pointer to that CEvents will be
146 * This will block until any one of the CEvents in the group are
147 * signaled or the timeout is reachec. If an event is signaled then
148 * it will return a pointer to that CEvent, otherwise it will return
151 CEvent* wait(unsigned int milliseconds);